The invention relates to a method for the fabrication of synthetic-material component assemblies having components which are formed by blow-molding and are preferably coated with a decorative material at parts of their surface.
In order to achieve a visually and tactilely attractive surface, components fabricated from synthetic material by the process of blow-molding are coated with a decorative material which is backed in addition with a layer of foamed material in order to improve the tactile qualities, for example through the use of a soft, flexible yielding surface.
Normally, the components are fabricated in a first process step from an extruded synthetic-material tube by the extrusion blow-molding process. Components formed in that way are known to possess a high rigidity and it is possible during the blow-molding process to mold on diverse functional elements such as air channels, mechanical guides, devices for fixing, pockets and the like, at the same time.
The decorative material is attached by gluing during a second process step. However, that step is complicated since the surface of the component must be activated when using polypropylene in order to ensure the adhesive properties. The application of the glue to specific parts of the surface also presents difficulties since for that purpose it is necessary to use templates or to protect the border or edge areas of the component from glue.
In addition to the complicated working procedure, prior art methods for the fabrication of synthetic-material components with decorative surfaces have the further disadvantage that a simple recycling of used components is not guaranteed.
It is accordingly an object of the invention to provide a method for the fabrication of synthetic-material component assemblies having components in the form of blow-molded parts coated on parts of their surface, which overcomes the hereinafore-mentioned disadvantages of the heretofore-known methods of this general type and which enables coating with a decorative surface to be performed exactly, even in border or edge areas, and with little outlay.
With the foregoing and other objects in view there is provided, in accordance with the invention, a method for the fabrication of synthetic-material component assemblies, which comprises initially pressing a decorative material in a cold or heated state to produce a composite decorative element; inserting the composite decorative element in a blow-molding die; and blow-molding a component in the blow-molding die while pressing and fusing the composite decorative element to coat at least part of an outer surface of the component.
In this way, synthetic-material components with decorative areas backed with foamed material can be fabricated rapidly, with little work outlay and to a high quality.
In accordance with another mode of the invention, the prefabricated composite decorative element can already be preformed to the contour of the relevant component.
In accordance with a further mode of the invention, the composite decorative element is pressed together flat and then, after being previously heated if necessary, is shaped during blow-molding together with the component to be formed and combined with the outer surface thereof at the same time.
In accordance with an added mode of the invention, the shaping in the blow-molding die or of the pre-shaped composite decorative element takes place in such a way that during blow-molding a decorative groove is formed in the component, namely in a region corresponding to a peripheral edge of the composite decorative element, into which decorative groove the bent-over edge of the composite decorative element is recessed.
In accordance with an additional mode of the invention, the synthetic-material component including the decorative coating backed with foamed material is formed from a single-material system of polypropylene, and the composite decorative element is formed of polypropylene textile as the decorative material and of extruded and/or expanded polypropylene as the backing of foamed material. It is also possible, however, to use thermoplastic polyolefin and the like, or synthetic leather, leather and similar material, as the decorative material.
Thus, according to this method, it is possible to fabricate partially coated components which not only meet the high requirements of aesthetic construction, tactile quality and durability but also satisfy the need for simple recycling and which, in addition, can be fabricated with little outlay.
Other features which are considered as characteristic for the invention are set forth in the appended claims.
Although the invention is illustrated and described herein as embodied in a method for the fabrication of synthetic-material component assemblies, it is nevertheless not intended to be limited to the details shown, since various modifications and structural changes may be made therein without departing from the spirit of the invention and within the scope and range of equivalents of the claims.
The construction and method of operation of the invention, however, together with additional objects and advantages thereof will be best understood from the following description of specific embodiments when read in connection with the accompanying drawings.